Ultra-wide band (UWB) active electronically scanned array (AESA) antennas (also known as phased array antennas) are important for next generation signal intelligence (SIGINT, such as electronic intelligence (ELINT) and communications intelligence (COMINT)) systems and for multi-function electronic warfare (EW), communications, and radar systems.
Existing UWB AESA antennas are expensive to manufacture and heavy. Proper electrical performance of UWB AESA antennas requires precise electrical interaction between printed circuit board (PCB) antenna radiating elements (e.g., balanced antipodal Vivaldi antenna radiating elements) and a radiating element containment and ground plane structure (sometimes referred to as a cradle, an “egg crate”, or an “egg crate chassis”). For example, the radiating element containment and ground plane structure should have precisely designed shunt capacitance to ground between PCB antenna radiating elements and channels (e.g., U-shaped slots) of posts of the radiating element containment and ground plane structure. Additionally, UWB AESA antenna designs require precise mechanical tolerances in the radiating element containment and ground plane structure.
Because of the required precise electrical interaction and mechanical tolerances associated with the radiating element containment and ground plane structure, current radiating element containment and ground plane structures are costly to manufacture. Existing radiating element containment and ground plane structures are fabricated from a solid billet of aluminum by using a complex numerical control (CNC) machining process and a wire electrostatic deposition machining (EDM) process. Currently, each of the posts of the radiating element containment and ground plane structure are fabricated by performing the CNC machining process to remove aluminum from the solid aluminum billet which leaves the ground plane base and a plurality of posts. Existing wire EDM processes also include forming channels (e.g., U-shaped slots) in each post and PCB insertion slots in the ground plane base by using a wire electrode to burn through aluminum material one slot at a time. Because the radiating element containment and ground plane structure may include thousands of posts and thousands of slots, which are formed one at a time, such CNC machining and wire EDM processes are expensive and time consuming. Additionally, the resulting aluminum radiating element containment and ground plane structure is very heavy.